Plenty of wave energy to be harvested close to shore

SINCE the oil crisis of the 1970s kick-started interest in wave power, it has become received wisdom that only offshore waves are worth tapping into. As a result, the varied designs competing to rule the waves have been banished to distant, deep waters where conditions are rougher and engineering costs highest.

Now a reassessment suggests that waves closer to shore are not such puny prospects after all, raising the hope that harvesting energy from waves will become easier and more economical than previously imagined.

Statisticians took to the seas in the 1970s. They used data from weather ships and buoys and calculated that the waves passing a 1-metre-wide slice of water at a 50-metre-deep "offshore" location carry an average power of 40 kilowatts, double the power density of waves in 10-metre-deep waters nearer the shore.